2 dead cylinders
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
2 dead cylinders
I did some work on the car,Had the heads off,new lifters,pushrods,shaft mount roller rockers,Honed the cylinders,new rings,rod bearings,Put everything back together and cylinders # 7 & #8 not firing,Swapped coils,plugs,wires,injectors still nothing,Its getting spark,The injector has the same ohm's as all the other injectors,Also the same voltage with the key on.Changed out the ECM still the same,Changed crank sensor.Checked compression,All 150psi,A little low have to break in the new rings.I turned the motor over with the valve cover off,Everything looked good.I don't know what else to check,Am I missing something
Any idea's?
Any idea's?
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
So you've confirmed without doubt there is a spark on both at all ( relevant ) times ?
You're confirming fuel is being injected ? Or just you believe the injector is getting a signal ?
Try swapping injector wires so cyl 5 is feeding 7 and 6 feeding 8 etc and see of the non-fire moves to 5/6 ?
Are those plugs wet, dry, other ?
How much lifter pre-load did you hit prior to rebuild ? Can you loosen it easily for a test ?
You're confirming fuel is being injected ? Or just you believe the injector is getting a signal ?
Try swapping injector wires so cyl 5 is feeding 7 and 6 feeding 8 etc and see of the non-fire moves to 5/6 ?
Are those plugs wet, dry, other ?
How much lifter pre-load did you hit prior to rebuild ? Can you loosen it easily for a test ?
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
So you've confirmed without doubt there is a spark on both at all ( relevant ) times ?
You're confirming fuel is being injected ? Or just you believe the injector is getting a signal ?
Try swapping injector wires so cyl 5 is feeding 7 and 6 feeding 8 etc and see of the non-fire moves to 5/6 ?
Are those plugs wet, dry, other ?
How much lifter pre-load did you hit prior to rebuild ? Can you loosen it easily for a test ?
You're confirming fuel is being injected ? Or just you believe the injector is getting a signal ?
Try swapping injector wires so cyl 5 is feeding 7 and 6 feeding 8 etc and see of the non-fire moves to 5/6 ?
Are those plugs wet, dry, other ?
How much lifter pre-load did you hit prior to rebuild ? Can you loosen it easily for a test ?
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Then add a short piece of wire for the test.
Repeatedly swapping injectors isnt going to give you a different result if you've already done that.
And whilst you havent directly said it...this engine has not run correctly at all since you put it back together ?
Repeatedly swapping injectors isnt going to give you a different result if you've already done that.
And whilst you havent directly said it...this engine has not run correctly at all since you put it back together ?
Supporting Vendor
Joined: Apr 2012
Posts: 2,671
Likes: 369
From: Forney TX
I'm a bigger fan of isolating the problem over throwing parts at it until the problem goes away. I would recommend putting a stethoscope on the injectors and listening for their opening and closing action. It's something you'll be able to hear. If the injectors are clicking, move on to the coils. I have a number of things to test the coils for function. One of them is an old timing light where I clip on the inductive clamp and verify that the light flashes. I also have an oscilloscope with an inductive clamp that can be used on both the power and/or ground inputs of the coils and injectors. It is possible to analyze the signals and tell if the injector pintle is actually moving. It's also possible to tell if the coil is firing through the spark plug with some experience. You can compare the neighboring cylinder signals to get an idea of what they should look like. It's not the cam signal. If the cam signal is lost, the PCM transitions to an alternate mode but continues to function and the engine continues to run properly.
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Offering products from A&A Superchargers, East Coast Superchargers, Mechman Alternators, Mantic clutches, RPS clutches, Kooks Headers, Lakewood, LG, Brian Tooley Racing, Comp Cams, FAST, ARP, UPP Turbo systems, Wiseco, Callies, K1, MAST Motorsports, Haltech and many more. PM me for details.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Like I said I do have P1336 crank learn code,I've had it before and it never gave me a problem,I would do a crank relearn with EFILive and all was good.I looked that code up on EFILive website and some guy's say they had the same symptoms I'm having.I'm off tomorrow so I will give it another shot.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
I'm a bigger fan of isolating the problem over throwing parts at it until the problem goes away. I would recommend putting a stethoscope on the injectors and listening for their opening and closing action. It's something you'll be able to hear. If the injectors are clicking, move on to the coils. I have a number of things to test the coils for function. One of them is an old timing light where I clip on the inductive clamp and verify that the light flashes. I also have an oscilloscope with an inductive clamp that can be used on both the power and/or ground inputs of the coils and injectors. It is possible to analyze the signals and tell if the injector pintle is actually moving. It's also possible to tell if the coil is firing through the spark plug with some experience. You can compare the neighboring cylinder signals to get an idea of what they should look like. It's not the cam signal. If the cam signal is lost, the PCM transitions to an alternate mode but continues to function and the engine continues to run properly.
Last edited by DRIVER456; Feb 21, 2017 at 05:42 PM.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Given the symptoms, and the fact it is a new build so to speak, the chances of those cylinders being off for anything wiring, coil or injector related are probably fairly slim.
But all the tests mentioned above are fairly easy to do to rule them out. But given it has never run correctly since rebuild....a trigger problem of some sort is possible which could be causing those cylinder not to receive any fuel....but as a cause of the trigger problem, not a fault with the outgoing circuits.
As for crank/cam etc....are you sure the cam/gear is installed correctly ? Could the crank trigger wheel have been damaged in any way when things were apart ?
Crank sensor wiring etc all ok ?
http://www.ls2.com/boggs/dtcs/DTC%20P1336.htm
But all the tests mentioned above are fairly easy to do to rule them out. But given it has never run correctly since rebuild....a trigger problem of some sort is possible which could be causing those cylinder not to receive any fuel....but as a cause of the trigger problem, not a fault with the outgoing circuits.
As for crank/cam etc....are you sure the cam/gear is installed correctly ? Could the crank trigger wheel have been damaged in any way when things were apart ?
Crank sensor wiring etc all ok ?
http://www.ls2.com/boggs/dtcs/DTC%20P1336.htm
Last edited by stevieturbo; Feb 21, 2017 at 06:09 PM.
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Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Given the symptoms, and the fact it is a new build so to speak, the chances of those cylinders being off for anything wiring, coil or injector related are probably fairly slim.
But all the tests mentioned above are fairly easy to do to rule them out. But given it has never run correctly since rebuild....a trigger problem of some sort is possible which could be causing those cylinder not to receive any fuel....but as a cause of the trigger problem, not a fault with the outgoing circuits.
As for crank/cam etc....are you sure the cam/gear is installed correctly ? Could the crank trigger wheel have been damaged in any way when things were apart ?
Crank sensor wiring etc all ok ?
http://www.ls2.com/boggs/dtcs/DTC%20P1336.htm
But all the tests mentioned above are fairly easy to do to rule them out. But given it has never run correctly since rebuild....a trigger problem of some sort is possible which could be causing those cylinder not to receive any fuel....but as a cause of the trigger problem, not a fault with the outgoing circuits.
As for crank/cam etc....are you sure the cam/gear is installed correctly ? Could the crank trigger wheel have been damaged in any way when things were apart ?
Crank sensor wiring etc all ok ?
http://www.ls2.com/boggs/dtcs/DTC%20P1336.htm
Last edited by DRIVER456; Feb 21, 2017 at 06:20 PM.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
OK I got it,I tried my other PCM just for the hell of it and it worked,No more P1336 code,Revs up no popping spittin out of the exhaust.I don't know why it worked this time.My other PCM is a Roadrunner from Moates with real time tuning,I had that in there since 2008 so I can't complain.Those 2 back cylinders are still colder then the rest,But it idles fine.So I either have to look at other after market computers or solder the RR guts to this PCM.Thanks for the replies/help guy's.
AMP Racing
Joined: Aug 2006
Posts: 10,755
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
Roadrunner?? Bah! HPTuners FTW
PS. Glad you got it running.
PS. Glad you got it running.
Last edited by C5 Pete; Feb 22, 2017 at 06:27 PM.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
OK I got it,I tried my other PCM just for the hell of it and it worked,No more P1336 code,Revs up no popping spittin out of the exhaust.I don't know why it worked this time.My other PCM is a Roadrunner from Moates with real time tuning,I had that in there since 2008 so I can't complain.Those 2 back cylinders are still colder then the rest,But it idles fine.So I either have to look at other after market computers or solder the RR guts to this PCM.Thanks for the replies/help guy's.
Same tune in each or different ?
Was anything done that might have corrupted the tune in one of them ?
Welding with ecu plugged in, maybe jump starting or something ? What about loading the tune from the working one back into the other to see what happens ?
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 3,088
Likes: 61
From: NY- 2013 Corvette Challenge Champion-2013 Index Combo Champion 2015 CC/MM Champion
St. Jude Donor '07
I forgot one thing,I put the ohm meter on the 2 crank sensor's I had,Came up with 2 different readings,So I ran to autozone,Bought a crank sensor,put that in and thats when I tried the other PCM,So it had to be a combination of both ,the sensor and the RR pcm.Stevie I think what screwed it up was I hit the positive wire on the alternator and arced for a split second.Yea I read on efilive website about the P1336 code,You can read another good PCM,save the case data and flash it into the RR pcm the do a calibration flash only.I did try that but nothing,I will try again today now that I it working.
Last edited by DRIVER456; Feb 23, 2017 at 07:34 AM.
